The present invention relates to heating devices such as wood and coal burning stoves, incinerators, and the like, and more particularly to an auxiliary exhaust system for use with a flue that aids venting and provides a combustion control for such heating units.
Heating units such as coal or wood burning stoves have become popular for use in residential homes due to the ever increasing cost of electricity and natural gas. The use of such heating units, however, also poses several objectionable problems. One such problem is the escape of smoke or carbon monoxide gas from the heating unit into the home when the feed door of the unit is opened to refuel the fire. Another problem is the potential fire hazard which may occur due to the buildup of creosote in the flue and chimney when burning wood or the buildup of soot when burning coal.
Another problem associated with such residential heating units is draft control. Coal and wood burning stoves require an adequate supply of air in order to promote the most efficient combustion of the fuel. If the supply of air is insufficient, the stove is burning inefficiently due to the passage of unburned gases into the flue. If the supply of air is in excess of that required, the stove is burning inefficiently due to the absorption of heat by the excess air passing into the flue. In the past, air for combustion has generally been provided by the natural draft occurring as the hot gases of combustion flow from the combustion chamber through the flue to the chimney which draws air through vents located in the stove. The amount of air supplied through natural draft, however, is subject to wide variations due to weather and atmospheric conditions. In addition, the flue may be improperly installed resulting in the occurrence of poor or inadequate venting. Thus, natural draft will not always provide the ideal air supply to promote efficient combustion.